Disclosed is an analyte detection method for detecting an analyte contained in a biological sample, constituted by irradiating a light of a first peak wavelength on a complex containing an analyte and fluorescent substance which gives off light of a second peak wavelength of 450 nm or higher but not exceeding 900 nm when irradiated with light of the first wavelength of 190 nm or higher but not exceeding 350 nm, detecting the light of the second peak wavelength given off by the fluorescent substance when irradiated by light of the first peak wavelength, by a photodetector, wherein the photodetector has a quantum efficiency in the second peak wavelength that is two or more times the quantum efficiency in the first peak wavelength.